Breaking Through Back-Drilling Inspection Bottlenecks: Zhongdun Technology Launches the AXI-S700XL-P, Ushering in a New Era of 3D Non-Destructive Full Inspection for PCB Back-Drilling
The High-Speed Signal Era: The "Unbearable Burden" of Back-Drilling Quality Control
With the explosive growth of high-speed applications such as AI servers, data centers, and 5G communications, PCB signal rates have surged from 25Gbps to 112Gbps, and even beyond 224Gbps. In multilayer PCBs, the unconnected copper columns remaining in vias-known as back-drill stubs-act like antennas, generating severe signal reflection, distortion, and crosstalk, thereby becoming a critical bottleneck for transmission speeds. High-quality back-drilling requires stub lengths to be controlled within 0.1mm (or ≤0.05mm for high-frequency applications); exceeding these limits directly leads to large-scale communication failures.
However, the back-drilling process is highly susceptible to factors such as equipment precision and drill bit wear, resulting in critical defects like excessive stub length, off-center drilling, or missed holes. Even more challenging is the fact that traditional inspection methods are already overwhelmed:
Cross-section sampling: A destructive test that scraps the sample; it offers only a single viewing angle and extremely low efficiency. Electrical testing: Detects only existing short or open circuits but cannot pinpoint potential risks like stub length. 2D X-ray: Struggles to accurately quantify stub boundaries due to the overlapping of multiple copper layers.
Market demand for back-drill inspection is rapidly shifting from "random sampling" to "micron-level, in-line" non-destructive full inspection. Yet, the global 3D AXI equipment market has long been monopolized by overseas giants, with production capacity already locked in through 2026–2027-making domestic substitution an urgent imperative.
Zhongdun Technology AXI-S700XL-P: Engineered for Back-Drilling Inspection
Against this industry backdrop, Wuxi Zhongdun Technology Co., Ltd. (hereinafter "Zhongdun Technology") has officially launched the AXI-S700XL-P, a fully automated, in-line 3D X-ray inspection system. As the latest addition to the S700 series, this equipment is specifically designed for back-drilling inspection in the PCB industry. Centered on reconstruction-based tomographic inspection technology and powered by proprietary AI algorithms, it overcomes the inherent limitations of traditional inspection methods.
Four Core Advantages Redefining Back-Drilling Inspection Standards
① In-line 3D, High-Speed Automated Full Inspection
The AXI-S700XL-P supports continuous 24-hour in-line inspection, enabling 100% full inspection rather than mere sampling. It utilizes horizontal 360° orbital projection (planar CT) technology, where the object remains stationary while the detector and X-ray source rotate horizontally around it. With an inspection speed as fast as 1.7 seconds per Field of View (FOV)-complemented by 30fps high-speed dynamic image output and multi-axis linear motor "fly-shot" capabilities-it captures 128 image samples in just 5 seconds, ensuring production line efficiency is never compromised by the inspection process.
② Flexible Multi-Mode Adaptation, Versatile Functionality
The system supports multiple inspection modes-2D, 2.5D, and 3D-allowing for flexible switching based on specific products and inspection requirements. Whether for rapid screening or in-depth analysis, a single machine covers the entire workflow.
③ Proprietary Algorithms, Micron-Level Precision Quantification
Its self-developed planar CT algorithms enable millisecond-level 3D reconstruction and support volumetric data slicing and analysis. With image resolution reaching 4–20μm, the system precisely identifies residual back-drill stub lengths, hole wall quality, and interlayer alignment, effectively resolving the industry-wide challenge where traditional 2D X-ray systems fail to accurately quantify stub boundaries.
④ 3D Imaging with No Blind Spots, Leaving Defects Nowhere to Hide
The system not only provides real-time, high-definition cross-sectional views of the object's interior but also generates 3D rendered volumetric images. Defects associated with the back-drilling process-such as missed drills, off-center drilling, over-drilling (too deep), under-drilling (too shallow), and stub length issues-are clearly visible through 3D perspective imaging.
High-Performance Specifications Empowering High-End Manufacturing
The AXI-S700XL-P is equipped with a 130kV (optional 150kV) micro-focus X-ray source and a high-definition flat-panel detector, covering a maximum inspection area of 950mm × 660mm (at 20°) and 600mm × 660mm (at 45°). The system maintains a radiation leakage level of ≤0.5μSv/h and holds the "Su Huan Fu Zheng [B1839]" radiation safety license. Weighing approximately 4,700kg, the unit features a robust and reliable structure.
Real-World Case Studies: Data-Driven Results
In a back-drilling inspection application for a PCBA, the AXI-S700XL-P performed comprehensive scans across multiple zones, covering dozens of back-drilled holes. The stub length for each hole was precisely quantified and visually displayed. Dual-view (FRONT and RIGHT) displays simultaneously show the stub values for the selected hole, making inspection results immediately clear.
Flexible Line Solutions for Seamless Smart Factory Integration
Zhongdun Technology also offers a recommended production line layout for back-drill inspection, supporting a unidirectional flow: Loading Unit → Re-inspection Buffer → Inspection Unit → (Optional Return Loop) → Re-inspection Buffer → Final Return to Loading Unit for Unloading. With loading and unloading occurring on the same side and in the same direction, the system facilitates single-sided operation and space efficiency-ideal for narrow workshop environments and easy integration into automated production lines.
Seizing the Moment for Domestic Substitution: Zhongdun Technology Leads the "AI + Smart Inspection" Frontier
Founded in 2021 and headquartered in Wuxi, Jiangsu, Zhongdun Technology brings together a team of technical experts in the X-ray inspection field and has established an integrated technology platform combining hardware with AI algorithms. The company has accumulated extensive experience in applications such as IGBTs, chip packaging and testing, and SMT, providing high-performance inspection equipment and core algorithmic solutions to numerous industry-leading enterprises.
As the AI computing industry places increasingly stringent demands on PCB quality, back-drilling inspection is shifting from optional to mandatory, and from random sampling to comprehensive, 100% inspection. The launch of the AXI-S700XL-P not only fills the gap for domestically produced in-line 3D back-drilling inspection equipment in the high-end market but also introduces a new inspection paradigm-characterized by high speed, precision, non-destructive capabilities, and in-line operation-to deliver a truly effective 3D non-destructive inspection solution for high-end PCB manufacturing.
Quality control for back-drilling is moving beyond "destructive sampling" and into a new era of "micron-level, in-line, 100% inspection."